Method of and means for determining headlight adjustments



Oct. 27, 1931. s, 1 LEBBY 1,829,997

METHOD OF AND MEANS FOR DETERMINING HEADLIGHT ADJUSTMENTS Filed Sept. 17, 1.929

/fi Exam Lee Le y, jy w W Patented Oct. 27, 1931 UNITED STATES STATES LEE LEBBY, OF CORNING, NEW YORK METHOD OF AND MEANS'FOR DETERMINING HEADLIGHT ADJUSTMENTS Application filed September 17, 1929.

In the interests of safety and to comply with the laws of the various States, it is desirable and in fact imperative that motor vehicle head lights should be tested at intervals to determine if they are properly adjusted and to prevent glare. The laws of most States require that the head lights do not produce a beam intensity greater than 2400 candle power above the horizontal line of the head lights. Q

My present invention relates to improved method of and means or apparatus for deter mining if and when the headlights are properly adjusted and aims to provide apparatus 1 which will be of simple and economical nature and by which the intensity of the rays may be readily and accurately determined from a given point and preferably from the drivers seat, whereby he may drive his car into proper position relative to the apparatus and determine if his lights are properly adjusted without dismounting.

Apparatus according to the preferred embodiment of my invention is illustrated in the 5 accompanying drawing in which the figure is a perspective view. In this drawing, the numeral 1 designates a screen supported in an upright position and designed to be placed in a location where a motor vehicle may be driven in predetermined or designated position in front of it so that the light from the head lights is projected on the same and at a suitable distance therefrom, such motor vehicle being shown 5 conventionally in the drawing.

The top edge of this screen is of such height as to determine the brightness of the headlight rays along the top edge, which thus determines the glare intensity.

At a suitable distance beyond, but preferably relatively close to the screen 1 is located a second upright screen 2, which will be called the comparison light screen, and which may be of substantially the same material and height, but is preferably made considerably higher and has its surface 2a above the horizontal line 7) colored black, so as to absorb the headlight rays 0 passing above the top of screen 1. The portion of screen 2 below said black portion; i. e., below line 7),

Serial No. 393,299.

is colored white as indicated at 26. Or the height of screen 2 may be such that the headlight rays passing over screen 1 also pass just clear of its top edge, so as to avoid illuminating screen 2 by the light from the headlights. In order to avoid confusion, any walls in the immediate vicinity of the screens should be black.

At a suitable distance in front of portion- 2?) of screen 2 and behind screen 1, I place lighting means 3, such as a plurality of incandescent lamps by which the portion 26 of the comparison light screen 2, which is shielded by screen 1 from the light rays-of the head lights, may be illumined to the desired degree. Proper adjusting means, such for instance as a rheostat in the lighting circuit, may be used to fix the intensity of the illumination of the screen.

At (Z, I have indicated the eye line of the driver or other observer and it will'be observed that from his seat, he can see the portion of the comparison screen surface 27) over' the top of the screen 1.

With the lights 3 set to illuminate the surface 2bat the proper intensity prescribed. he can compare the brightness of the headlights If the headlight raysare aimed too high, the

top edgeiof screen 1 adjacent 2?) will appear bright, indicating a glare condition. But if the beams are aimed too low, the top edge of screen 1 will appear dark against 26. Thus any difference in degree of illumination can thereby be readily detected and if there be. any difference, the head lights may be raised or lowered until the respective surfaces of screen 1 and 2 are illuminated to equal intensity. This indicates that the proper adjustment has been achieved.

If the background is of proper character, screen 2 need not be extended above line b, but by extending it higher and coloring the upper portion black, I secure a proper contrast to the portion 26.

The top line of screens 1 and 2 need not necessarily be straight, but may be curved or their height varied at points, and the intensity of the light on the comparison screen varied at points, so that means for determining the intensity limits of even a non-uniform headlight distribution may be accomplished.

Headlights may thus be maintained free from glare as prescribed by law or in case the beams are too low, which results in reduced driving efiiciency, they can be raised to the limit allowed by law, and thus be kept at highest efficiency Without glare. 7

Having thus described my invention, What Iclaimis: i

1. Means for use in adjusting headlights comprising a screen positioned to receive the h light from said headlights a comparison screen shielded from" said headlights by the first mentioned screen and so placed as to have at least a portion thereofvisible from a given point simultaneously ith the first named screen, and means for illuminating said comparison screen to a predetermined intensity.v v i a V,

2. Means for use in adjusting headlights comprising ascree'n positioned to receive, the lightpfrom said headlights, a comparison screen shielded from said headlights. by the first mentionedv screen and so placed asto i have at least a portionthereof visible from a given point simultaneously With the first named screen, andjvari'able means for illu: minating said comparison screen. v Q

1 3, Means for use in adjusting headlights comprising a screen positioned to receive the light from said headlights, a comparison screen shielded from said headlights by. the first fmentioned screen and so placed as to have at least a portion thereof visible from a given. point simultaneously with; the; first named. screen, and having ,a dark portion above the level of the top of the first named screen'for contrast, and means for illuminate ing said comparison screen to atpredeterg mined intensity.

4. Means for use in adjusting head ights comprising a screen positionedto receive the light from said headlights, a comparison screen shielded'frQm Said" headlights, the first mentioned screen fsaid, screens being so placed" that the first screen and at least a 7 portion of the comparison screen-are visible from the drivers seat simultaneously, and means for illum natin g the comparison screen i to a predet'ermlned intensity.

' stares LEE LEBBYL testimony h reo f, I aflix. signat re; 

